The present invention relates to a structure for a wheel, and more particularly, to a wheel of a stationary bicycle and the wheel having two pivotable plates on which magnets are connected so that when pulling braking wire of the stationary bicycle the plates and the magnets on the plates are moved relative to a magnetic field damping device.
A conventional stationary bicycle 100 as shown in FIG. 1 has a frame with a seat tube on which a set 1 is connected, a crank 12, a first wheel 13 is co-axially connected to the crank 12, and a second wheel 15 which is connected to the first wheel 13 by a chain 14. A user may sit on the seat 1 and rotates the crank 12 by his/her feet stepping on the pedals 120 to rotate the second wheel 15. In order to increase the exercising feature of the stationary bicycle, a damping device is cooperated with the wheel so as to increase the resistant force while the wheel is rotated by the user. The damping device includes a magnetic field damping device 18 and the second wheel 15 is co-axially connected to a free-fly wheel 27 and an Aluminum wheel 16. When rotating the crank, the distance between the Aluminum wheel 16 and the magnetic field damping device 18 will generate different damping force applied to the Aluminum wheel 16 so as to achieve different exercising purposes.
FIG. 2 shows an improved Aluminum wheel 20 known to applicant wherein the body of the wheel 20 is made of cast iron and a plurality of notches are defined in a periphery of the wheel 20. A ring-shaped Aluminum 300 is mounted to the wheel 20 and includes a plurality of protrusions 320 which fill in the notches so as to reduce the quantity of Aluminum and therefore reduces the manufacturing cost.
The present invention intends to provide a wheel that is used in a stationary bicycle that involves a magnetic field damping device. The wheel includes two plates eccentrically and respectively connected to an inside of the wheel and each plate has magnets connected thereto. A wire is connected to the plates so that when pulling the plates, the curvature of the plates is changed and the distance between the magnets and the magnetic field damping device is adjusted to generate different levels of damping force.
In accordance with one aspect of the present invention, there is provided a wheel for a stationary bicycle having a magnetic field damping device. The wheel comprises a first disk having a plurality of rods and first protrusion extending from a side of the first disk. A second disk has a plurality of second protrusion extending from aside of the second disk so that a plurality of rollers are connected between the first protrusion and the second protrusion that are in alignment with each other. A first plate has a first end thereof pivotably connected at a first point between the first disk and the second disk. A plurality of magnets are connected to the first plate. A second plate has a first end thereof pivotably connected at a second point between the first disk and the second disk. A plurality of magnets are connected to the first plate. A wire is connected to a second end of the first plate and a second end of the second plate.
The object of the present invention is to provide wheel structure that has a simple structure and movable magnets which are moved by pulling a wire so as to adjust the distance between the magnets and a magnetic field damping device.
There and further objects, features and advantages of the present invention will become more obvious from the following description when taken in connection with the accompanying drawings which show, for purposes of illustration only, several embodiments in accordance with the present invention.